A conventional throttle control apparatus is disclosed in "Leone New Car Features July, 1984" issued by Fuji Heavy Industries Ltd. The throttle control apparatus disclosed in this publication includes a vacuum pump installed in the engine compartment and a vacuum actuator disposed in the passenger compartment of the vehicle.
The vacuum actuator of the throttle control apparatus is driven by negative air pressure supplied from the vacuum pump in order to move the accelerator pedal connected to the vacuum actuator. The accelerator pedal controls the throttle opening of the engine.
In accordance with this known throttle control apparatus, the vacuum actuator does not have to be connected to the accelerator pedal with a cable because the vacuum actuator is not disposed in the engine compartment. Therefore, undesirable sliding resistance is not generated when the vacuum actuator is operated. Further, the throttle control apparatus can be manufactured at a relatively low cost because the throttle control apparatus does not require a complex link mechanism.
However, the throttle control apparatus does require a vacuum tube that connects the vacuum pump and the vacuum actuator. This vacuum tube must pass or extend through the dashboard that separates the engine compartment from the passenger compartment. For this reason, an opening is provided in the dashboard through which the vacuum tube extends. Thus, a seal member must be fitted in the opening in the dashboard to prevent rain water from entering the passenger compartment. Further, the vacuum tube must be located in the engine compartment. This construction increases the cost associated with outfitting the vehicle with such a throttle control apparatus.
In light of the foregoing, a need exists for a throttle control apparatus which is relatively less expensive to implement in a vehicle.